A Combined D.C. Optimization—Ellipsoidal Branch-and-Bound Algorithm for Solving Nonconvex Quadratic Programming Problems

In this paper we propose a new branch-and-bound algorithm by using an ellipsoidal partition for minimizing an indefinite quadratic function over a bounded polyhedral convex set which is not necessarily given explicitly by a system of linear inequalities and/or equalities. It is required that for this set there exists an efficient algorithm to verify whether a point is feasible, and to find a violated constraint if this point is not feasible. The algorithm is based upon the fact that the problem of minimizing an indefinite quadratic form over an ellipsoid can be efficiently solved by some available (polynomial and nonpolynomial time) algorithms. In particular, the d.c. (difference of convex functions) algorithm (DCA) with restarting procedure recently introduced by Pham Dinh Tao and L.T. Hoai An is applied to globally solving this problem. DCA is also used for locally solving the nonconvex quadratic program. It is restarted with current best feasible points in the branch-and-bound scheme, and improved them in its turn. The combined DCA-ellipsoidal branch-and-bound algorithm then enhances the convergence: it reduces considerably the upper bound and thereby a lot of ellipsoids can be eliminated from further consideration. Several numerical experiments are given.     

Improved estimators for the location of double exponential distribution

In this paper, attention is focused on estimation of the location parameter in the double exponential case using a weighted linear combination of the sample median and pairs of order statistics, with symmetric distance to both sides from the sample median. Minimizing with respect to weights and distances we get smaller asymptotic variance in the second order. If the number of pairs is taken as infinite and the distances as null we attain the least asymptotic variance in this class of estimators. The Pitman estimator is also noted. Similarly improved estimators are scanned over their probability of concentration to investigate its bound. Numerical comparison of the estimators is shown.     

Flood risk mapping and analysis using an integrated framework of machine learning models and analytic hierarchy process

In this study, a new approach of machine learning (ML) models integrated with the analytic hierarchy process (AHP) method was proposed to develop a holistic flood risk assessment map. Flood susceptibility maps were created using ML techniques. AHP was utilized to combine flood vulnerability and exposure criteria. We selected Quang Binh province of Vietnam as a case study and collected available data, including 696 flooding locations of historical flooding events in 2007, 2010, 2016, and 2020; and flood influencing factors of elevation, slope, curvature, flow direction, flow accumulation, distance from river, river density, land cover, geology, and rainfall. These data were used to construct training and testing datasets. The susceptibility models were validated and compared using statistical techniques. An integrated flood risk assessment framework was proposed to incorporate flood hazard (flood susceptibility), flood exposure (distance from river, land use, population density, and rainfall), and flood vulnerability (poverty rate, number of freshwater stations, road density, number of schools, and healthcare facilities). Model validation suggested that deep learning has the best performance of AUC = 0.984 compared with other ensemble models of MultiBoostAB Ensemble (0.958), Random SubSpace Ensemble (0.962), and credal decision tree (AUC = 0.918). The final flood risk map shows 5075 ha (0.63%) in extremely high risk, 47,955 ha (5.95%) in high-risk, 40,460 ha (5.02%) in medium risk, 431,908 ha (53.55%) in low risk areas, and 281,127 ha (34.86%) in very low risk. The present study highlights that the integration of ML models and AHP is a promising framework for mapping flood risks in flood-prone areas.     

The type I distribution of the ratio of independent “Weibullized” generalized beta-prime variables

In this paper we introduce the distribution of , with c >  0, where X _i , i =  1, 2, are independent generalized beta-prime-distributed random variables, and establish a closed form expression of its density. This distribution has as its limiting case the generalized beta type I distribution recently introduced by Nadarajah and Kotz (2004). Due to the presence of several parameters the density can take a wide variety of shapes.      

Techniques of Death: Buddhist Practice,Femininity and Self-Cultivation at the Last Stage of Life in Vietnam

This article explores how death is conceptualised by elderly lay Buddhist women in H? Chí Minh City (Vietnam). It explores the traits of a ‘good death’ which elderly laywomen wish to experience, and their dedicated practice of Buddhism to prepare themselves for a peaceful end stage of life. This article contends that, in fact, women’s perceptions of death speak to their desires to live a life with dignity and retain their full personhood and nurturing femininity which they have embodied throughout their adult lives even until their last moments. They pursue devotional practices to train their body and mind in order to prepare themselves for the critical moment of dying, believing that these self-cultivating practices will enable them to transcend physical suffering and mental confusion, and immediately move on to the next, better life.     

Lessons from the flipside: How do acquirers learn from divestitures to complete acquisitions?

We examine whether experience from prior divestitures is associated with higher completion likelihood in subsequent acquisitions. We argue that through divestitures, firms could extract meaningful knowledge that is helpful for completing their acquisitions, such as a general understanding of acquisition deal-making stages, and the stories and aims of the target in an M&A transaction. In addition, viewing divestitures as the flipside of acquisitions, we conjecture that the selling firm can observe how the divested component of their business is acquired, and vicariously learn from these observations. We also investigate the relative importance of learning from divestiture vis-à-vis acquisition experience in determining acquisition deal completion. Finally, we contend that the effect of learning from divestitures on acquisition deal completion depends on acquisition experience and deal value. We find evidence supporting our conjectures in a sample of 2164 M&A transactions from the worldwide computer and printing industries between 1991 and 2010.     

The right to fashion in the age of terrorism

As part of a feminist commitment to collaboration, this article appears as a companion essay to Mimi Thi Nguyen's "The Biopower of Beauty: Humanitarian Imperialisms and Global Feminisms" and offers a point of departure for thinking about fashion and beauty as processes that produce subjects recruited to, and aligned with, the national interests of the United States in the war on terror. The Muslim woman in the veil and her imagined opposite in the fashionably modern - and implicitly Western - woman become convenient metaphors for articulating geopolitical contests of power as a human rights concern, as a rescue mission, as a beautifying mandate. This article examines newer iterations of this opposition, in the wake of September 11, 2001, in order to demonstrate the critical resonance of a biopolitics on fashion and beauty. In "The Right to Fashion in the Age of Terrorism," the author examines the relationship between the U.S. war on terror, targeting persons whose sartorial choices are described as terrorist-looking and oppressive, and the right-to-fashion discourse, which promotes fashion's mass-market diffusion as a civil liberty. Looking at these multiple invocations of the democratization of fashion, this article argues that the right-to-fashion discourse colludes with the war on terror by fabricating a neoliberal consumer-citizen who is also a couture-citizen and whose right to fashion reasserts U.S.exceptionalism, which is secured by private property, social mobility, and individualism.     

Neglect of older adults in Michigan nursing homes

Although research on domestic elder abuse and neglect has grown over the past 20 years, there is limited research on elder neglect in nursing homes. The purpose of this study is to estimate the incidence of elder neglect in nursing homes and identify the individual and contextual risks associated with elder neglect. Data came from a 2005 random digit dial survey of individuals in Michigan who had relatives in long term care. Our analytic sample included 414 family members who had a relative aged 65 or older in nursing homes. Results showed that about 21% of nursing home residents were neglected on one or more occasion in the last 12 months. Two nursing home residents' characteristics reported by family members appear to significantly increase the odds of neglect: functional impairments in activities of daily living and previous resident-to-resident victimization. Behavior problems also are associated with higher odds of neglect (p = 0.078). Policy implications of these results are discussed.     

“I Am Tired But If I Don't Try to Have Sex,My Wife Will Think I've Been Fooling around in the City”: Work,Migration, and Sex Among Vietnamese Migrant Laborers

Mostly operating from a risk and risk-reduction paradigm, existing research on migrants in Vietnam tends to conceptualize sex and risky sexual behaviors as isolated life domains. This study begins to develop a contextually rich understanding of migrants’ sex lives by examining the relationships among sex, work, and the constant pendulum-like migrating movements of 23 Vietnamese married migrants in Hanoi and Ho Chi Minh City. Using data from in-depth interviews, it was found that most participants had no sex in the city; this was followed by visits to the home village, where they had sex with their spouses as often as possible to make up for the “long drought” in the city. Within this sexual schema, sex came secondary, and even peripherally, to migrants’ working lives; thus, exhaustion from work was cited by migrants as the overwhelming factor leading to their sexual problems. This study suggests that migrants’ intimate lives are more strongly linked to their working lives than has previously been recognized, and that their sexual behaviors should be viewed in tandem with the hardships of their working lives.     

Institutional,Subcultural, and Individual Determinants of Same-Sex Sexual Contact Among College Women

While the collegiate hookup literature identifies the prevalence and conditions under which women engage in same-sex sexual behaviors, less is understood about the macro- and mesolevel features of universities predictive of women’s engagement in these behaviors. How do predictors of same-sex contact differ for women who report engagement in nongenital versus genital sexual acts? Using the Online College Social Life Survey (OCSLS), this study examined 5,069 women from 21 U.S. colleges and universities who reported at least one same-sex encounter in their lifetime to empirically evaluate how same-sex sexual histories are predicted by university structure and membership in student subcultures. Results find subcultural participation to have a regulative effect on what types of sexual behaviors women engaged in with other women. While Greek-affiliated women were significantly more likely to have engaged in solely nongenital sexual behavior, women in team-based athletics were more likely to report a genital sexual history with women. This study’s focus on women’s sexual behaviors as opposed to sexual identity affirms the influence of institutional contexts, subcultural dynamics, and their variability across U.S. campuses in producing the conditions and opportunities for varied forms of sexual interactions among college women.